David Moyes was handed a six-year contract to become manager of Manchester United on Thursday, showing the deep belief the club have in naming the Scot as Sir Alex Ferguson's successor. Moyes was personally chosen for the job by Ferguson, with his recommendation being "unanimously" approved by the United board, an indication of how the outgoing manager will continue to be a strong influence on the direction of the club.

His first task will be dealing with the future of one of his star players, his old protege Wayne Rooney. The striker, who came through the ranks under Moyes at Everton, held showdown talks with Ferguson two weeks ago and told him that he wanted to leave in the summer due to his disgruntlement at being played out of position and being dropped for the Champions League last-16 second leg against Real Madrid at Old Trafford in February.

However, it is understood that Rooney's position may now have cooled following Moyes's appointment. If Rooney does decide that his future remains at Old Trafford, it would be the second time the 27-year-old has done a U-turn over his future – after his transfer request in 2010 – and he would face a struggle to win back support from United's fans.

Officially, the club are adamant that Rooney, who has two years left on his contract, is not for sale. Yet according to a highly placed source at the club the striker is valued in the £40m region, so if a serious offer is lodged it would be considered.

Moyes was Rooney's first manager when the Liverpudlian broke into Everton's first team in 2002. After the Scot sued Rooney over allegations in a biography the pair reconciled but whether Moyes would want him to stay at United is not yet clear, though he will have the final say on the striker's future.

Paris Saint-Germain retain a desire to sign Rooney, while Bayern Munich may wish to take him to Germany. Rooney has interested Chelsea in the past but there is an acceptance at Stamford Bridge that, as a No10, he would not fit easily into the current side. However, José Mourinho, who is likely to take over from Rafael Benítez, is an admirer of the 27-year-old and could still push for a move for him.

Moyes, who accepted replacing British football's most successful manager presents a sizeable challenge, was preferred over Mourinho due to the longevity of his 11-year tenure at Everton during which he rebuilt the club.

Ferguson said: "When we discussed the candidates that we felt had the right attributes we unanimously agreed on David Moyes. David is a man of great integrity with a strong work ethic. I've admired his work for a long time and approached him as far back as 1998 to discuss the position of assistant manager here. He was a young man then at the start of his career and has since gone on to do a magnificent job at Everton. There is no question he has all the qualities we expect of a manager at this club."

Moyes currently earns £80,000 a week – £4m a year – at Everton, which makes him better paid than any of the first-team squad and he will receive a hefty increase in these terms. The 50-year-old, who starts his tenure on 1 July, is free to bring in his own backroom staff at United, which puts the futures of Mike Phelan, the assistant manager, and first-team coach René Meulensteen in doubt.

While the Scot has yet to make any decisions in this area, Moyes is an admirer of Steve Round, his assistant at Everton, who he views as an innovative coach. Moyes had also wanted to add Phil Neville, his captain at Everton, to his support team at the Merseyside club. Although the 36-year-old declined due to his wish to play on, Neville has since registered an interest in replacing Moyes as Everton manager, so the potential offer of a position at United, his former club, would be attractive.

Moyes said: "It's a great honour to be asked to be the next manager of Manchester United. I am delighted that Sir Alex saw fit to recommend me for the job. I have great respect for everything he has done and for the football club. I know how hard it will be to follow the best manager ever, but the opportunity to manage Manchester United isn't something that comes around very often and I'm really looking forward to taking up the post next season.

"I have had a terrific job at Everton, with a tremendous chairman and board of directors and a great set of players. Between now and the end of the season, I will do everything in my power to make sure we finish as high as possible in the table. Everton's fantastic fans have played a big part in making my years at Goodison so enjoyable and I thank them wholeheartedly for the support they have given me and the players. Everton will be close to me for the rest of my life."

Sir Bobby Charlton, a director who was instrumental in bringing Ferguson to United in 1986, said: "We have secured a man who is committed to the long term and will build teams for the future as well as now. Stability breeds success."

Before the official confirmation United suffered the embarrassment of tweeting a link to their Facebook page that heralded Moyes's appointment. Although the tweet was quickly erased, it still became widely viewed via social media.